Under the minor league deal announced Wednesday, Bautista would receive a $1 million, one-year contract if added to the 40-man major league roster.
The six-time All-Star will report to the Braves' extended spring training complex in Lake Buena Vista, Florida, to work himself into game condition.
Bautista, 37, had been unsigned after spending the past 10 years with Toronto, where he emerged as one of baseball's most accomplished and feared sluggers.
Primarily a right fielder over the past eight years, Bautista has appeared in just 12 games at third base since the start of the 2012 season. He played more extensively at third earlier in his career, as a member of the Pittsburgh Pirates and in his early years with the Blue Jays.
Bautista hit at least 22 homers in each of the last eight seasons, including a career-best 54 for the Blue Jays in 2010. He has four seasons with at least 100 RBIs, though his production dipped significantly the last two years.
The signing is a low-risk move by the Braves to bolster their lineup, which currently has Ryan Flaherty at third base. Flaherty is off to a surprising start, hitting an NL-leading .354 through 14 games, but his career average is .221.
Bautista batted just .203 with 23 home runs and 65 RBIs last season, when he made $18 million. He has 331 homers and 927 RBIs in parts of 14 seasons with Toronto, Pittsburgh, Kansas City, Tampa Bay and Baltimore.
Information from The Associated Press contributed to this report.